As such an anti-vibration apparatus, for example, a configuration disclosed in the following Patent Document 1 is known. The anti-vibration apparatus includes a first attachment member having a tubular shape and connected to one of a vibration generating section and a vibration receiving section, a second attachment member connected to the other section, an elastic body configured to connect the attachment members to each other, a liquid chamber in the first attachment member in which a liquid is sealed, and a partition member which partitions the liquid chamber into a first liquid chamber and a second liquid chamber. The anti-vibration apparatus further includes a first restriction passage and a second restriction passage configured to bring the liquid chambers in communication with each other, a cylinder chamber installed between the liquid chambers, and a plunger member disposed in the cylinder chamber to be movable between an open position and a closed position.
A plurality of types of vibrations having different frequencies such as an idle vibration, a shake vibration, or the like, are input to the anti-vibration apparatus. Here, in the anti-vibration apparatus, resonant frequencies of the first restriction passage and the second restriction passage are set (tuned) to frequencies of different types of vibrations. Then, as the plunger member moves between the open position and the closed position according to the frequency of the input vibration, the restriction passage through which the liquid flows is switched to the first restriction passage and the second restriction passage.